With increasing age, osteoporosis becomes a common problem in women and occurs with increasing frequency in men. The main thrust of our studies has been towards a successful form of treatment for this disease. Preliminary work, already published, has suggested that a combination of fluoride, calcium and vitamin D will produce an increase in bone mass which should reverse the disease process and prevent further fractures. Long-term studies directed towards establishing exact dosage, evaluation of side effects and optimum duration of treatment is now underway. Further investigation in man are directed towards other possible forms of treatment, such as hormones, calcitonin and calcium; in particular, combined treatment is being evaluated. In both man and animals the importance of dietary intake, especially phosphate, is being studied in an attempt to delineate important factors in the etiology of the disease and to suggest forms of preventative therapy.